ES2615215T3 - Coating system - Google Patents

Abstract

A coating formed on a substrate, coating comprising a polymeric binder, (a) at least one organic pigment and / or at least one inorganic pigment; (b) at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; and (c) optionally, an effect pigment; wherein said coating has a total solar reflectance (TSR) of (i)> = 40%, if 60 <L * <100, or (ii)> = 30%, if 30 <L * <= 60, or ( iii)> = 20%, if 0 <L * <= 30, in which L * is the luminosity in the color space L * a * b * (CIELAB), in which the pigment (a) is a pigment near-infrared transparent organic (NIR) and / or an NIR reflective inorganic pigment, and coating that is an outdoor use coating selected from an industrial coating or a car coating.

Description

Coating system

The invention relates to a coating formed on a substrate comprising (a) an organic pigment transparent to NIR and / or an inorganic pigment reflecting NIR, (b) a dye having a transmittance of at least 75% in the range of wavelengths of 700-2500 nm and (c) optionally, an effect pigment. The coating system is suitable for an exterior use coating such as an industrial coating or a vehicle coating, especially for a car finish. In addition, the invention relates to the use of said dye to improve the degree of blackness of a coating.

Carbon black is widely used in coatings to impart a property known as "degree of blackness" to a black color. The color black, the more jet, appears more black than those that have lower blackness characteristics. The degree of blackness is a complex function of the surface area, the primary particle size and the degree of dispersion in the final coating. Carbon black is added to plastics or coatings not only to make the medium black, but also to change the dye characteristics of other colors. In addition, carbon black is often added in small quantities to car finishes of any color for processing safety reasons.

The jet black color of the car is created with carbon black, sometimes dyed with dyes to improve the degree of blackness. However, carbon black strongly absorbs invisible near-infrared (NIR) radiation that represents more than 50% of the total incident solar energy. This causes strong accumulated heat. In order to significantly reduce the effect of heating under sunlight, especially in dark tones, carbon black can be replaced by NIR transparent pigments or NIR reflective pigments, for example, with Color Index (CI) Black Pigment 32 o CI Brown Pigment 29 or pigment preparations based on them, etc. In the case of black coatings comprising carbon black, the total solar reflectance (TSR) is less than 5%, while the coatings comprising C.I. Black Pigment 32 or C.I. Brown Pigment 29, for example, achieves TSR values greater than 30% (the attainable TSR value depends on the color, formulation, substrate and film thickness). However, the use of said pigments in coating applications does not have the desired degree of blackness, but rather a blurred or milky dark coating is obtained.

WO 2008/097895 A2 describes a layered coating composition for use in the production of a dark and cold coating composition that includes an IR reflective layer having IR reflective pigments in a resinous binder, on which it is applied. as a coating a radiation absorbing layer that includes nanometric pigments dispersed in a resinous binder.

WO 2011/56564 A2 describes an IR reflective coating composition and cured coatings deposited on a substrate. Said composition comprises a colored and / or opaque crosslinked IR reflecting pigment and an IR transparent pigment, in which the cured coating shows a total solar reflectance of at least 15%.

DE 19834194 A1 describes dispersions for protective and / or decorative coatings comprising core-shell particles and, preferably, a dye. Organic-based paints having specific color effects are described, such as angle-dependent color effects, due to the difference in the refractive index of the core and shell polymeric materials.

There is a continuing need to improve the color characteristics and functionality of the coatings. Therefore, it is an objective of the present invention to provide a coating material that provides colorations that have advantageous performance properties, especially high gloss and improved chroma and blackness properties, in which the reduced heating effect under Sunlight should not be influenced.

It has been discovered that a coating formed on a substrate with the desired properties is obtained.

Accordingly, in a first aspect, the invention relates to a coating formed on a substrate comprising a polymeric binder,

(to)

an organic pigment and / or an inorganic pigment;

(b)

a dye having a transmittance of at least 75% in the range of 700 to 2500 nm; Y

(C)

optionally, an effect pigment;

wherein said coating has a total solar reflectance (TSR) of

(i)

≥ 40%, if 60 <L * <100, or

(ii)

≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if 0 <L * ≤ 30,

where L * is the luminosity in the color space L * a * b * (CIELAB),

5 in which the pigment (a) is a transparent pigment to NIR and / or an inorganic pigment reflective of NIR, and coating which is an outdoor use coating selected from an industrial coating or a coating for automobiles.

The TSR is measured according to the Method of ASTM E 903-96 using direct solar spectral irradiance of ASTM G159-98. The L * value is measured with an observation angle of 25 °.

Preferably, the invention relates to a coating formed on a substrate comprising

(to)

at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, at least one effect pigment;

wherein said coating is free of carbon black and has a TSR of

15 (i) ≥ 40%, if 60 <L * <100, or

(ii) ≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if 0 <L * ≤ 30,

in which L * is the luminosity.

Pigment (a) is a pigment transparent to NIR and / or an inorganic pigment reflective of NIR.

In a further preferred aspect, the invention relates to a coating formed on a substrate comprising

(to)

at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, at least one effect pigment;

25 wherein said coating has a TSR of

(i)

≥ 45%, if 60 <L * <100, or

(ii)

≥ 35%, if 30 <L * ≤ 60, or

(iii) ≥ 25%, if 0 <L * ≤ 30.

More preferably, the coating has a TSR of

30 (i) ≥ 50%, if 60 <L * <100, or

(ii) ≥ 40%, if 30 <L * ≤ 60, or

(iii) ≥ 30%, if 0 <L * ≤ 30.

The term "total solar reflectance" (TSR) used herein is the reflected percentage of energy radiated from the sun in the wavelength range of 300 to 2500 nm. TSR measurements are made

35 according to the Method of Standard ASTM E 903-96 ("Solar Absorptance, Reflectance and Transmittance of Materials Using Integrating Spheres", "Solar Absorption, Reflectance and Transmission of Materials Using Integrating Spheres"), using direct solar spectral irradiance of ASTM G159-98. The TSR values are determined by applying the coating on a white surface.

The term "near infrared" (NIR) used herein means the wavelength range 40 from 700 nm to 2500 nm.

The expression L * (luminosity) used in this document means the luminosity in the color space L * a * b * (also called CIELAB) specified by the International Lighting Commission, in which a * and b * are the coordinates of chromaticity. The L * value is measured with an observation angle of 25 °. According to the CIELAB system, L * = 100 means the lightest value (white), L * = 0 means the darkest value (black). In general, a

L * value refers to an opaque coating.

The expression C * (chroma) used herein means chroma in the color space L * C * h (also called CIELAB) specified by the International Lighting Commission, in which L * is the same brightness as in The color space L * a * b * and h is the hue angle.

The term "transparent to NIR" used herein means that a sample predominantly transmits NIR radiation and does not predominantly absorb or reflect NIR radiation.

The term "NIR reflective" used herein means that a sample predominantly reflects NIR radiation and does not predominantly transmit or absorb NIR radiation.

The term "coating" or "coating system" used herein means a film or layer applied on a substrate and dried and / or cured, that is, final for use. The coating, or the coating system, may comprise one or more layers.

The pigment (a) may in principle be any functional pigment, provided that the pigments are transparent

or reflective in the NIR wavelength range of 700 to 2500 nm. Pigment (a) can be at least one organic pigment that is transparent to NIR or at least one inorganic pigment that is reflective of NIR or a mixture thereof. At least one organic pigment can be a mixture of up to 10 different pigments, preferably 2 to 5 pigments. At least one inorganic pigment can be a mixture of up to 10 different pigments, preferably 2 to 5 pigments.

The pigments used herein are preferably present in a finely dispersed form. Generally, organic pigments have an average primary particle size of 800 nm or less, preferably 500 nm or less and, more preferably, 200 nm or less. Inorganic pigments generally have an average particle size of 0.1 to 5 µm, especially 0.1 to 3 µm and, in particular, 0.1 to 1 µm. The average particle size can be determined according to DIN ISO 13320: 2009.

The NIR transparent organic pigment can be a chromatic or black organic pigment. For example, the organic pigment can be a perylene pigment, a phthalocyanine pigment, a diketopyrrolopyrrole pigment, an indigo pigment, a thioindigo pigment, an anthraquinone pigment, an indatrone pigment, an azo pigment monoazo, disazo and azometin, condensation pigment disazo, isoindoline pigment, quinacridone pigment, benzimidazolone pigment, pyrazoloquinazolone pigment, perinone pigment, dioxazine pigment or a pigment preparation of said pigments.

Preferably, the coating of the invention comprises a perylene pigment, a phthalocyanine pigment, a dioxazine pigment, a dicetopyrrolopyrrole pigment, an indigo pigment, an anthraquinone pigment, a monoazoic pigment, quinacridone, an isoindoline pigment, a benzimidazolone pigment, a pyrazoloquinazolone pigment or a pigment preparation of one of said pigments.

Specific examples of suitable NIR transparent pigments may be Color Index (C.I.) Yellow Pigment 110, 139, 151; C.I. Orange Pigment 69, 73; C.I. Pigment Red 122, 179, 202, 254, 282; C.I. Brown Pigment 29; C.I. Violet Pigment 19; C.I. Blue Pigment 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 60; C.I. Green Pigment 7, 36;

C.I. Black Pigment 31 and 32.

Preferred organic pigments are black pigments based on perylene, for example C.I. Black Pigment 31 and (N, N'-diphenylethyleneperylene-3,4: 9,10-tetracarboximide and N, N'-di (p-methoxythiolyl) -perylene-3,4: 9,10 tetracarboximide, respectively). In addition, a perylene pigment, as described in WO 2005/078023 A2, comprising one of the isomers of the general formula Ia or Ib or a mixture thereof,

wherein R1, R2 are each independently phenylene, naphthylene or pyridylene, each of which may be mono- or polysubstituted with C1-C12 alkyl, C1-C6 alkoxy, hydroxy, nitro and / or halogen; X is halogen; and n is 0 to

4. A preferable pigment of said formulas is a perylene pigment comprising one of the isomers of the general formula 'or Ib' or a mixture thereof,

in which R1 and R2 are the same and are naphthylene or unsubstituted phenylene, especially a mixed cis / trans isomer

or of the formula Ia / Ib, in which R1 = R2 = 1,2-phenylene; n = o R1 = R2 = 1,8-naphthylene; n = 0; or a mixture of cis / trans isomers of the formula Ia '/ Ib', in which R1 = R2 = 1,2-phenylene or R1 = R2 = 1,8-naphthylene.

Suitable organic pigments are commercially available under the registered trademarks Paliotol® Yellow L 2146 HD, Irgazi Yellow L 2110, Chromopthal® Yellow L 1061 HD, Heliogen® Green L 9361, Heliogen® Green L 8735, Heliogen® Blue L 6960 HD, Heliogen® Blue L 6905 F, Heliogen® Blue L 6700 F, Paliogen® Blue L 6480, Paliogen® Blue L 6360, Paliotol® Orange L 2930 HD, Irgazin® Orange L 2990 HD, Irgazin® Orange L 3250 HD, Irgazin® Red L 3660 HD, Irgazin® Red L 3670 HD, Paliogen® Red L 3885, Paliogen® Red L 3920, Cinquasia® Magenta L 4400, Cinquasia® Violet L 5120, Cromophtal® Violet GT, Hostaperm® Violet RL, Hostaperm® Rosa E, Paliogen® Black L 0086, Paliogen® Black EH 0788 and Lumogen® Black FK 4281.

The inorganic pigment (b) can be any NIR reflective pigment, for example, C.I. Pigment Yellow 53, 184, C.I. Pigment Brown 24, 29, 33, 35, C.I. Pigment Blue 28, 36, C.I. Green Pigment 17, 26, 50, or C.I. Pigment Black 12, 30.

Suitable organic pigments are commercially available under the trademarks Sicotan® Yellow L 2110, Sicotan® Yellow L 1910, Sicopal® Yellow L 1120, Sicotan® Yellow L 1010, Sicopal® Green K 9710, Sicopal® Blue L 6210, Sicopal® Orange L 2430 and Sicopal® Black L 0095.

The pigments (a) mentioned above can also be used in the form of suitable pigment preparations. Organic pigment preparations generally comprise derivatives of said pigments, derivatives that may contain part or all of the pigment chromophore in its molecular structure and, preferably, have acidic or basic groups. Pigment derivatives can be conveniently prepared by partially reacting a pigment with suitable reagents, thereby preferably forming pigments on whose surface stains or a continuous or discontinuous layer of the derivative are present. In addition, useful pigment preparations may comprise nonionic surfactant additives based on polyethers and / or water soluble anionic surfactant additives based on acidic esters of these polyethers, on ethylenically unsaturated carboxylic acid polymers and / or on polyurethanes. Suitable examples are described in WO 03/64540, WO 03/66743, WO 04/00903, WO 0429159, WO 04/46251, WO 04/50770 and US 2008/0190319.

Suitable organic pigment preparations are commercially available, for example, under the registered trademarks Luconyl® NG Yellow 1260, Luconyl® NG Yellow 2350, Luconyl® NG Green 9360, Luconyl® NG Green 8730, Xfast® Green 8730, Luconyl® NG Blue 7080 , Luconyl® NG Blue 6900, Xfast® Blue 7080, Xfast® Blue 6875, Luconyl® NG Orange 3100, Xfast® Orange 3100, Luconyl® NG Red 3750, Luconyl® NG Red 3860, Xfast® Red 3860, Luconyl® NG Magenta 4790 , Xfast® Magenta 4790 and Luconyl® NG Violet 5300.

Suitable inorganic pigment preparations are commercially available, for example, under the registered trademarks Luconyl® NG Yellow 1102, Luconyl® NG Yellow 1995, Xfast® Yellow 1102, Xfast® Yellow 1990, Luconyl® NG Green 9990, Xfast® Green 9990, Luconyl ® NG Turquoise 9110, Luconyl® NG Blue 6310, Luconyl® NG Blue 6120, Xfast® Blue 6310, Luconyl® NG Orange 2430, Luconyl® NG Red 3395, Xfast® Red 3390, Luconyl® NG Black 0095, Xfast® Black 0095, Luconyl® NG White 0022 and Xfast® White 0025.

The at least one dye (b) may in principle be any dye, provided that the dye transmits at least 75% in the NIR wavelength range of 700 to 2500 nm. Preferably, the transmittance is at least 80%, more preferably at least 85%. The transmittance is measured in an ethanol solution (1% or 0.4% by weight, 1 mm cuvette).

Preferably, the dye (b) used has, in each case, a shade that is comparable to the pigments (a), in order to achieve a particularly intensive coloration of the coating materials. However, it is also possible to use a dye (b) that differs in hue, thus allowing the coloration to darken. Preferably, a dye or a mixture of two or three dyes is used.

Suitable dyes can be selected from azo dyes, azometin dyes, xanthene dyes, anthraquinone dyes, metal complex dyes or phthalocyanine dyes, preferably metal complex dyes.

Specific examples may be C.I. Yellow Solvent 79, 81, 82, 88 and 89; C.I. Orange Solvent 11, 54, 56 and 99;

C.I. Brown Solvent 42, 43 and 44; C.I. Red Solvent 118, 122, 125, 127, 130, 160, 199 and 233; Blue solvent 67 and 70; And ci. Black solvent 27, 28 and 29.

Suitable colorants may also be those commercially available under the trademark Orasol® Yellow 152, 190, 081, 141, 157; Orasol® Orange 245, 251, 247, RG, 272; Orasol® Brown 322, 324, 326; Orasol® Red 330, 385, 363, 335, 355, 365, 395, 471; Orasol® Pink 478; Orasol® Blue 825, 855, GL; Orasol® Black X45, RLI, X51 and X55.

Preferably, the coating system comprises the dye (b) in an amount of 0.01 to 10.0% by weight, for example 0.1 to 8.0% by weight, preferably 0.3 to 8.0 % by weight, more preferably 0.5 to 6.0% by weight and, more preferably, 0.8 to 3.0% by weight, based on the total weight of the pigment (a).

Dyes that are not soluble in the application medium can also be used in combination with a suitable emulsifier. For example, a metal complex dye, such as C.I. Black Solvent 29, which can be dispersed in water, can be used with a suitable emulsifier as a non-ionic surfactant in aqueous formulations.

Optionally, the coating comprises an effect pigment (c) that provides a bright effect that is advantageously used in a car coating.

The effect pigments (c) are laminar pigments generally used in effect coatings such as metallic pigments, for example, those of titanium, aluminum or copper; interference pigments such as metallic pigments coated with metallic oxide, for example aluminum coated with titanium dioxide or mixed oxides or aluminum flakes coated with iron oxide (for example, Paliocrom® effect pigments), coated mica, for example coated mica with titanium dioxide or mixed oxides, microtitanium dioxide, laminar iron oxide (micaceous iron oxide), molybdenum sulphide pigments, bismuth oxychloride flakes, coated glass flakes. Metallic pigments, interference pigments or coated mica pigments are preferred, coated mica pigments are especially preferred.

Accordingly, the invention also relates to a coating formed on a substrate comprising a polymeric binder,

(to)

an organic pigment and / or an inorganic pigment;

(b)

a dye having a transmittance of at least 75% in the range of 700 to 2500 nm; Y

(C)

an effect pigment;

wherein said coating has a TSR of

(i)

≥ 40%, if 60 <L * <100, or

(ii)

≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if0 <L * ≤ 30, and L * is the brightness in the color space L * a * b * (CIELAB),

wherein the pigment (a) is a transparent pigment to NIR and / or an inorganic pigment reflective of NIR, and coating which is a coating for external use selected from an industrial coating or a coating for automobiles.

Preferably, the coating comprises the effect pigment (c) in an amount of 0.1 to 60% by weight, preferably 1 to 50% by weight, more preferably 20 to 40% by weight, based on the total weight of pigment (a). The presence of effect pigments can have a significant influence on TSR values in relation to an organic pigment transparent to NIR and / or an inorganic pigment reflecting NIR. For example, an increasing amount of a mica pigment coated with TiO2 increases the TSR value of a coating comprising a NIR transparent organic pigment and / or a NIR reflective pigment, preferably an NIR transparent organic pigment.

Preferred combinations of pigment (a) / dye (b) are, for example,

C.I.

Pigment Black 32 and C.I. Solvent Black 29;

C.I.

Pigment Black 31 and C.I. Solvent Black 29;

C.I.

Pigment Black 32 and C.I. Blue Pigment 15: 2 and C.I. Solvent Black 29;

C.I.

Pigment Black 31 and C.I. Blue Pigment 15: 2 and C.I. Solvent Black 29;

C.I.

Brown Pigment 32 and C.I. Solvent Black 29;

C.I.

Brown Pigment 29 and, optionally, a black perylene pigment such as C.I. Pigment Black 32 and

C.I.

Solvent Black 29;

C.I.

Pigment Blue 60 and Solvent Blue 70;

C.I.

Pigment Blue 15.1 and Solvent Blue 70;

C.I.

Pigment Blue 15.2 and Solvent Blue 70;

C.I.

Pigment Blue 15.3 and Solvent Blue 70;

C.I.

Pigment Blue 15.4 and Solvent Blue 70;

C.I.

Pigment Blue 15.6 and Solvent Blue 70;

C.I.

Pigment Red 254 and C.I. Red Solvent 122.

Said combinations may also comprise one or more effect pigments.

Advantageously, the coating comprises a black pigment which can be an NIR transparent organic pigment or an NIR reflective inorganic pigment, and an additional NIR transparent chromatic organic pigment. The amount of the black pigment may vary depending on the desired color of the coating. The amount of the black pigment (a ') can be from 3 to 95% by weight, based on the total weight of the pigment (a). In particular, the black pigment (a ') is combined with a transparent pigment to the blue NIR or a transparent pigment to the green NIR.

The NIR transparent organic pigment can be used in a coating applied on a NIR reflective substrate or formulated in combination with NIR reflective inorganic pigments.

IR reflective pigments can be used independently of the substrate, although the effect can be further enhanced using a reflective substrate.

It must be ensured that IR radiation is reflected either by the coating system itself or by its bottom, which can be achieved by adding foreign particles that have a high level of dispersion in the IR region, such as titanium dioxide pigments and inorganic pigments mixed phase (eg Sicotan® pigments, BASF), or foreign particles that have a high level of reflection in the IR region, such as aluminum flakes and bright pigments, for example those based on coated aluminum platelets, to the composition coating, or using metallic backgrounds or white backgrounds that have diffuse dispersion.

Any substrate material can be coated with the coating of the present invention, including materials such as glass, ceramics, plastics, smooth surface compounds and metal substrates. In particular, the coating of the present invention is particularly adapted for metal substrates or plastic substrates. The substrate can be a simple substrate material or, in the case of metal substrates, can be pretreated to impart corrosion resistance such as phosphating, or electrodeposition as cathodic immersion coating or other similar treatments well known in the art.

Examples of metal substrates that can be coated with the coating system of the present invention include steel, aluminum, titanium, alloys thereof, etc.

The coating is an outdoor use coating selected from an industrial coating or a car coating, including a car finishing system.

Accordingly, the invention relates to a coating as described in any previous aspect, which is an industrial coating or a coating for automobiles. A coating comprising an effect pigment is especially suitable for a multilayer coating for the automotive industry. The effect pigments are normally incorporated in the base layer layer, as described below.

The coating comprises a polymeric binder that can be, in principle, any binder customary in the industry. The polymeric binder may be a film forming binder, for example, a thermosetting film forming binder or a thermoplastic film forming binder. The amount of dyes, that is, the pigment (a), the dye (b) and, optionally, the effect pigment (c) may be in the range of 5 to 40% by weight, preferably 10 to 30% by weight , based on the nonvolatile part of the coating composition applied.

Components (a), (b) and, optionally, (c) may be incorporated by known methods in any coating formulation of various solids contents, such as low solids content coating compositions (<30% by weight of part nonvolatile) (30-60% by weight), medium solids coating compositions (60-70% by weight) or high solids coating compositions (> 70% by weight). Solvent or aqueous based formulations can be used. The components (a), (b) and, optionally,

(c) they can also be incorporated into powder coatings that have a solids content of almost 100%.

The coating can be a single layer system or a multilayer system. The thickness of a coating of a single layer system may be 30 to 200 µm, preferably 50 to 150 µm and, more preferably, 70 to 100 µm. A multilayer system may optionally comprise a primer, one or two layers of basecoat, and a clearcoat, which is generally for a coating for the automotive industry. The thickness of the coating as a whole can be from 30 to 200 µm, preferably from 50 to 150 µm and, more preferably, from 70 to 100 µm.

In a multilayer system, a primer is generally applied on top of the electrolytic coating layer that is approximately 20-40 µm thick. A primer may comprise white pigments such as titanium dioxide (C.I. White Pigment 6), zinc white, pigment grade zinc oxide, zinc sulphide or lithopone, preferably titanium oxide. The primer may also comprise NIR reflective pigments as described above, for example, C.I. Pigment Yellow 53, 184, C.I. Pigment Brown 24, 29, C.I. Blue Pigment 28 or C.I. Green Pigment 50. In the case of more base layers, one of the base layers can also replace a primer layer.

The base layer material, which imparts the desired color to the car body by appropriate pigments, may comprise any suitable film forming material conventionally used in this technique. Film-forming materials suitable for use in the formulation of the base layer compositions include, for example, acrylics, alkyd resins, polyurethanes, polyesters and aminoplast resins. As long as the binders are curable binders, they are usually used together with a hardener and / or an accelerator.

The base layer can be deposited outside an aqueous vehicle or conventional volatile organic solvents such as aliphatic, cycloaliphatic and aromatic hydrocarbons, esters, ethers, ketones and alcohols, for example, toluene, xylene, butyl acetate, acetone, methyl isobutyl ketone, butyl alcohol, etc. and mixtures thereof.

The transparent layer material, which imparts the desired gloss, may comprise any suitable film-forming material conventionally used in this technique, for example, combinations of alkyd resin-thermosetting melamine or thermosetting acrylics or polyurethane resins. Commercially available examples may be the transparent layers of the Duraclear® or Ureclear® trademarks.

The base layer and the transparent layer can be applied by any conventional method in this technique, such as brushing, spraying, dipping, flow coating, etc. Normally spray application is used, especially for car finishes. Various types of spraying can be used, such as compressed air spraying, electrostatic spraying, hot spraying techniques, airless spraying techniques, etc. The application of the coating system of the present invention generally follows the application to the substrate of a conventional corrosion resistant electrolayer or layer. To this substrate a primer can be applied as a coating, said layer being created largely by applying a coating to the oven, for example, by high-rotation electrostatic hoods and subsequent baking at temperatures above 130 ° C. A base coat can be applied on it in one or two layers. The base coat is generally applied with a thickness of about 10 µm to about 60 µm and, preferably, of

about 12 µm to about 30 µm. This thickness can be applied in a single pass of coating or in a plurality of passes with very short drying ("instant vaporization") between layer applications.

Once the base coat is applied, the top coat or clear coat can be applied after let the base layer be removed by instant vaporization, dried and, optionally, cured, for example, by thermal curing. The transparent layer composition can also be applied wet on wet on a base layer composition. The transparent layer is generally applied thicker than the previous layer. (preferably with a thickness of approximately 25 µm to 60 µm) and can also be applied in a single or in Several passes.

When appropriate, additives may also be used routinely as additional ingredients in the coating system Suitable additives may be, for example, surfactants, dispersants, waxes, fillers, defoamers, anti-dust agents, diluents, preservatives, dryness retardants, control additives rheological, wetting agents, antioxidants, UV absorbers, light stabilizers or combinations of same.

The additives may be present in an amount of 0 to 20% by weight, preferably 0-10% by weight, Based on the total weight of the coating.

To color a coating composition, the coloring components (a), (b) and, optionally, (c) and the organic film forming material comprising the high molecular weight organic material may, in generally, finely dispersed or dissolved, optionally together with the aforementioned additives, in a organic and / or aqueous solvent or in a solvent mixture using methods conventionally known in The technique.

The coating of the invention preferably comprises an organic pigment transparent to NIR as the pigment (a), and the substrate is a metal substrate as defined above.

The coating of the invention may also comprise more than one layer, as mentioned previously. The dye may be comprised in one or more layers.

Accordingly, the coating of the invention is preferably a multilayer coating, said multilayer comprises a primer, a base layer comprising one or two layers and a transparent layer as outer layer, in which the organic pigment (a) is comprised in the base layer, the inorganic pigment (a) is included in the primer, and the dye (b) is comprised in the transparent layer or in the base layer.

In particular, the coating of the invention is a multilayer coating, said multilayer comprises a primer, a base layer comprising one or two layers and a layer transparent as an outer layer, in which the organic pigment (a) is comprised in the base layer, the inorganic pigment (a) is included in the primer, and the dye (b) is comprised in the transparent layer.

A coating is further preferred, in which the coating is a multilayer coating that is defined as before, and the organic pigment (a) is comprised in the base layer, the dye (b) is comprised in the transparent layer or in the base layer, and The primer comprises a white pigment such as titanium dioxide (C.I. White Pigment 6), zinc white, zinc oxide of pigment quality, zinc sulphide and lithopone, preferably titanium oxide.

The coating of the invention may also comprise at least one organic pigment (a) and at least one inorganic pigment (a) in the same layer, for example, in the base layer. The base layer can comprise additionally the dye (b). Alternatively, the transparent layer may comprise the dye (b).

The optional effect pigment may be present in the base layer. In the case of two base layers, the Optional effect pigment is preferably present in the layer adjacent to the transparent layer.

Therefore, the coating of the invention is preferably a multilayer coating, said multilayer comprises a primer, a base layer comprising one or two layers and a layer transparent as an outer layer, in which the organic pigment (a) and the effect pigment (c) are comprised in the base layer, the inorganic pigment (a) is included in the primer, and

the dye (b) is comprised in the transparent layer or in the base layer.

A coating is further preferred, in which the coating is a multilayer coating defined as above, and the organic pigment (a) and the effect pigment (c) are comprised in the base layer, the dye (b) is comprised in the transparent layer or in the base layer, preferably in the transparent layer, and the primer comprises a white pigment as defined above.

A coating in any aspect described above herein is especially preferred, wherein the dye (b) is comprised in the outer layer such as the transparent layer. Alternatively, a coating is also especially preferred, in which the dye (b) is comprised in the base layer, in the case of two base layer layers in the layer adjacent to the transparent layer layer.

The coating of the invention is especially suitable for dark and black coatings, for example, dark blue or black coatings. In general, said coatings have a luminosity L * of ≤ 30. Black coatings may have a luminosity of ≤ 2 (preferably ≤ 15, especially ≤ 12).

A more preferred coating is a black coating based on a black NIR transparent perylene pigment and, optionally, a blue NIR transparent pigment and a black dye as described above. The perylene pigment can be used in combination with a blue NIR transparent pigment, for example, a phthalocyanine pigment such as C.I. Blue Pigment 15: 2, 15: 6 or an indantrone pigment as

C.I. Blue Pigment 60. The perylene pigment and, optionally, a blue pigment can be combined with a dark NIR reflective inorganic pigment such as C.I. Brown Pigment 29 in the same coating layer. The inorganic pigment may also be present in an underlying layer, such as the primer. Alternatively, only one transparent pigment to the NIR can be present in one layer. In both alternatives, the dye may be present in the same layer as the organic pigment or the dye may be present in the coated layer over the layer comprising the organic pigment.

Therefore, in a preferred aspect, the coating comprises

(to)

a perylene pigment and / or C.I. Brown Pigment 29, and

(b)

a dye selected from the group consisting of C.I. Black solvent 27, 28 and 29, preferably C.I. Black solvent 29.

In addition, in a preferred aspect, the coating comprises

(to)

a perylene pigment and / or C.I. Brown Pigment 29,

(b)

a dye selected from the group consisting of C.I. Black solvent 27, 28 and 29, preferably C.I. Solvent Black 29, and

(C)

optionally, an effect pigment, preferably a metallic pigment, an interference pigment or a coated mica pigment.

The perylene pigment can be at least one of the group consisting of C.I. Black Pigment 31, 32 and a perylene pigment of the formula Ia or Ib, especially of the formula Ia 'or Ib', or a mixture thereof.

Therefore, a more preferred coating is a coating comprising

(to)

at least one perylene pigment and / or C.I. Brown Pigment 29,

(b)

a dye selected from the group consisting of C.I. Black solvent 27, 28 and 29, preferably C.I. Solvent Black 29, and

(C)

optionally, an effect pigment, preferably a metallic pigment, an interference pigment or a coated mica pigment.

wherein the perylene pigment is selected from the group consisting of C.I. Black Pigment 31, 32 and a perylene pigment comprising one of the isomers of the general formula Ia 'or Ib' or a mixture thereof,

in which R1 and R2 are the same and are naphthylene or unsubstituted phenylene.

The coating based on a perylene pigment and / or C.I. Brown Pigment 29, as described above, may have a total solar reflectance of at least 20%, preferably at least 25

5% and especially at least 30%. The luminosity L * may be in the range of 0 to 30, preferably 0 to 20, more preferably 0 to 15, especially 0 to 12. Preferably, the coating comprises an effect pigment in an amount of 0.1 to 20% by weight, preferably 0.1 to 10%, based on the pigment (a).

In a preferred aspect, the invention relates to a coating comprising a polymeric binder

10 (a) a perylene pigment and / or C.I. Brown Pigment 29,

(b)

a dye selected from the group consisting of C.I. Black solvent 27, 28 and 29, and

(C)

optionally, an effect pigment, preferably a metallic pigment, an interference pigment or a coated mica pigment.

in which the coating has a TSR of at least 25% and L * is ≤ 20, especially ≤ 15.

If a chromatic coating is desired, for example, a blue or red coating, the dye may be present in a monolayer coating or in any layer of a multilayer coating. In all chromatic embodiments, the improved color depth may be indicated primarily by an improved chroma. In a black coating, the improved color depth is indicated primarily by an improved degree of blackness.

In addition, in a preferred aspect, the coating comprises

(to)

an organic pigment selected from the group consisting of C.I. Blue Pigment 15: 1, 15: 2, 15: 3, 15: 4, 15: 6 and 60 and / or an inorganic pigment selected from the group consisting of C.I. Blue Pigment 28 and 36;

(b)

a dye selected from the group consisting of C.I. Blue solvent 67 and 70; Y

25 (c) optionally, an effect pigment, preferably a metallic pigment, an interference pigment or a coated mica pigment.

in which the coating has a TSR of

(ii) ≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if0 <L * ≤ 30, in which L * is the luminosity.

In a further aspect, the invention relates to the use of a dye having a transmittance of at least 75% in the wavelength range of 700 to 2500 nm to improve the degree of blackness of a coating having a reflectance total solar

(i) ≥ 40%, if 60 <L * <100, or

(ii) ≥ 30%, if 30 <L * ≤ 60, or 35 (iii) ≥ 20%, if 0 <L * ≤ 30, where L * is the brightness in the color space L * a * b * ( CIELAB),

wherein the coating formed on a substrate comprises a polymeric binder,

(to)

at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, an effect pigment,

40 in which the pigment (a) is a near-infrared transparent organic pigment (NIR) and / or an inorganic pigment reflecting NIR, and coating which is an outdoor use coating selected from a

industrial coating or a coating for automobiles.

Preferably, the dye having a transmittance of at least 75% in the wavelength range of 700 to 2500 nm is C.I. Black solvent 27, 28 or 29, preferably C.I. Black Solvent 29. Accordingly, the invention relates to the use of C.I. Black solvent 27, 28 or 29, especially C.I. Solvent Black 29, to improve the degree of blackness in a coating that has a TSR of ≥ 20%, if 0 <L * ≤ 30, in which L * is the luminosity.

In a further aspect, the invention relates to the use of a dye having a transmittance of at least 75% in the wavelength range of 700 to 2500 nm to reduce the luminosity L * of the coating having a TSR of

(i)

≥ 40%, if 60 <L * <100, or

(ii)

≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if0 <L * ≤ 30, in which L * is the luminosity.

In a further aspect, the invention relates to a process for coating the surface of a substrate, a process comprising the consecutive steps of

(i)

applying a coating composition comprising a polymeric binder, and

(to)

at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, an effect pigment;

(ii)

optionally, remove the solvent, and

(iii) form a coating as defined in any aspect described above.

The coating may have a thickness of 30 to 200 µm.

Preferably, step (i) of the process includes an application stage of a base layer composition and the subsequent application of a transparent layer composition, wherein the component (a) and, optionally, (c) are comprised in the base layer composition and component (b) is comprised in the base layer or transparent layer composition.

Film formation or curing can be performed by physical or chemical drying, which is known in the art and generally depends on the polymeric binder used. Physical drying may be the evaporation of organic solvents and / or water or the cooling of polymer melts when a powder coating is used. Chemical drying may be the reaction of binder components, for example, by polymerization or crosslinking, with heat or radiation. Normally, the curing may comprise instantaneous vaporization at room or elevated temperature followed by thermal baking. In some embodiments, drying may occur at room temperature of about 20 to about 180 ° C. Normally, the base layer and the transparent layer will be cured in one step, optionally together with the primer.

The coatings of the invention provide excellent color and chroma depth, respectively, and blackness, especially in automotive finishes and industrial coatings. They show bright colors and an exceptional brightness for all color tones without the presence of milky appearance or blurry or subtle. The use of the dye has no influence on the absorption of NIR. Chroma is enhanced, especially in dark coatings, such as blue or green coatings. In addition, the shelf life of the coated material is increased. The coatings show excellent light and weather fastness.

The following examples illustrate the invention without limiting the scope thereof (when not specified otherwise, the% and parts are by weight).

Examples

L * a * b * color measurements are made using a Delta Color Spectraflash 600 device. TSR measurements are made with the UV-VIS-NIR spectrometer, Varian Cary 5000.

The following dye mixtures are incorporated into a conventional solids medium base layer composition (cellulose acetate butyrate (CAB), melamine / polyethylene (PE) and n-butyl acetate). The resulting coating composition (weight ratio of dye / binder 0.18) is applied by spray coating and drying at room temperature to give a coating thickness of 10 to 15 µm. An Alupanel panel coated with a primer comprising a white pigment is used as a substrate. The base layer is coated with a 1K transparent coating of a thickness of approximately 40 µm.

Example 1

4.90 parts of MagnaPearl® 3103 (mica coated with titanium dioxide)

4.90 parts of Heliogen® Blue L 6960 (C.I. Pigment Blue 15: 2)

22.06 parts Paliogen® Black EH 0788 (a perylene pigment)

66.18 parts of Paliogen® Black L 0086 (C.I. Pigment Black 32)

1.96 parts of Neozapon® Black X55 (= Orasol® Black X55) (C.I. Black Solvent 29)

Example 2

4.81 parts of MagnaPearl® 3103

4.81 parts of Heliogen® Blue L 6960

21.63 parts of Paliogen® Black EH 0788

64.90 parts of Paliogen® Black L 0086

3.84 parts of Neozapon® Black X55

Example 3

4.72 parts of MagnaPearl® 3103

4.72 parts of Heliogen® Blue L 6960

21.22 parts of Paliogen® Black EH 0788

63.68 parts of Paliogen® Black L 0086

5.66 parts of Neozapon® Black X55

Comparative Example 1

5 parts of MagnaPearl® 3103

5 parts of Heliogen® Blue L 6960

22.5 parts of Paliogen® Black EH 0788

67.5 parts of Paliogen® Black L 0086

Table 1

∆L *

TSR (%)

Comparative Example 1

Reference L * = 9.4 25

Example 1

-0.9 25

Example 2

-1.5 25

Example 3

-2.5 25

The resulting ∆L * values show the improved blackness of the black coatings compared to the coating without a dye. According to the color space L * a * b * (also known as CIELAB), L * indicates the brightness and a * and b * the chromaticity coordinates. A lower L * value means a higher level of blackness. A visual difference of ∆L * ≥ 0.3 can be recognized by an expert in the field as an improvement.

Example 4

The following dye mixture is incorporated into a conventional content base layer composition medium in solids (CAB, melamine / PE, n-butyl acetate). The resulting coating composition (the weight ratio of dye / binder is 0.18) is applied by spraying and drying at room temperature to produce a coating thickness of 10-15 µm.

33.3 parts of Paliogen® Black EH 0788 66.7 parts of Paliogen® Black L 0086

A transparent coating layer (one-component acrylic transparent layer) containing 1% by weight of Neozapon® Black X55 applied to the base layer was applied by spray (wet on wet) and dried at 130 ° C for 1 hour ( approximate thickness 40 µm).

Comparative Example 2

33.3 parts of Paliogen® Black EH 0788 66.7 parts of Paliogen® Black L 0086

A transparent layer without dye is applied on the base layer.

Comparative Example 3

A transparent layer without dye is applied, but with 1% by weight of Heliogen® Blue L 6960 on the base layer.

Table 2

∆L *

TSR (%)

Comparative Example 2

Reference L * = 9.4 26

Comparative Example 3

0 26

Example 4

-6.2 25

The difference in brightness of -6.2 shows a much improved degree of blackness compared to a dye-free coating. The presence of a transparent pigment to the NIR does not influence the degree of blackness.

Example 5

The following dye mixture is incorporated into a conventional content base layer composition medium in solids (CAB, melamine / PE, n-butyl acetate). The resulting coating composition (the weight ratio of dye / binder is 0.18) is applied by spraying and drying at room temperature to produce a coating thickness of 10-15 µm.

50 parts of Lumina® Pearl Radiance 1303D (mica pigment coated with TiO2)

24.9 parts of Heliogen® Blue L 6905 (C.I. Pigment Blue 15: 2)

24.9 parts of Heliogen® Blue L 6950 (C.I. Pigment Blue 15: 1)

0.2 parts of Orasol® Blue 855 (Blue 70 Solvent).

Example 6

The following dye mixture is incorporated into a conventional solids medium base layer composition (cellulose acetate butyrate (CAB), melamine / polyethylene (PE) and n-butyl acetate). The resulting coating composition (the weight ratio of dye / binder is 0.18) is applied by spraying and drying at room temperature to produce a coating thickness of 10-15 µm. The coating has a bright blue color.

50 parts of Lumina® Pearl Radiance 1303D

25 parts of Heliogen® Blue L 6905

25 parts of Heliogen® Blue L 6950

A transparent coating layer containing 0.2% by weight of Orasol® Blue 855, based on 100% by weight of the transparent coating composition, is applied to the base layer by spraying and drying at 130 ° C for 1 hour (thickness of approximately 40 µm).

Comparative Example 4

Example 6 is repeated, with the exception that the following mixture of dyes is used:

50 parts of Lumina® Pearl Radiance 1303D 25 parts of Heliogen® Blue L 6905 25 parts of Heliogen® Blue L 6950

Table 3

∆L *

∆C * TSR (%)

Comparative Ex 4

Reference L * = 40.8 C * = 46.8 38

Example 5

-0.7 0.4 38

Example 6

-2.9 1.7 37

The effect of an improved degree of blackness and an improved chroma can be shown for a blue coating, in which the effect on a transparent tinted layer is more significant.

10 The chroma of the chromatic coating can also be improved. One skilled in the art can recognize a visual difference of ∆C * ≥ 0.3.

Example 7

Example 6 is repeated, with the exception that the following mixture of dyes is used in the base layer:

50 parts of Stapa Metallux 3560 (aluminum pigment)

15 25 parts of Heliogen® Blue L 6905 25 parts of Heliogen® Blue L 6950

A transparent coating layer containing 0.2% by weight of Orasol® Blue 855, based on 100% by weight of the transparent coating composition, is applied to the base layer by spraying and drying at 130 ° C for 1 hour (thickness of approximately 40 µm).

20 Comparative Example 5

Example 5 is repeated, with the exception that the following mixture of dyes is used:

50 parts of Stapa Metallux 3560 25 parts of Heliogen® Blue L 6905 25 parts of Heliogen® Blue L 6950

25 Table 4

∆L *

∆C * TSR (%)

Comparative Ex 5

Reference L * = 69.7 C * = 52.8 41

Example 7

-7.8 9.1 41

Comparative Example 6

Comparative example 1 is repeated, with the exception that the following mixture of dyes is incorporated into a conventional base layer composition of medium solids content.

22.8 parts of Paliogen® Black L 0086 8.5 parts Heliogen® Green L 8735 (C.I. Pigment Green 7) 50 parts of Sicopal® Black L 0095 (C.I. Pigment Brown 29)

18.7 parts of Cromophtal® Violet GT (C.I. Pigment Violet 23)

The TSR value of said dark blurry coating is 28.4 and L * is 9.5.

Example 8

Example 1 is repeated, with the exception that the following dye mixture is incorporated into a conventional base layer composition of medium solids content.

21.92 parts of Paliogen® Black L 0086 8.17 parts of Heliogen® Green L8735 48.08 parts of Sicopal® Black K 0095 17.98 parts of Cromophtal® Violet GT

10 3.85 parts of Neozapon® Black X55

A glossy black coating is obtained showing a TSR of 28.4 and an improved degree of blackness, that is, a reduced L *.

Claims (14)

1. A coating formed on a substrate, coating comprising a polymeric binder,

(to)

at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, an effect pigment;

wherein said coating has a total solar reflectance (TSR) of

(i)

≥ 40%, if 60 <L * <100, or

(ii)

≥ 30%, if 30 <L * ≤ 60, or

(iii) ≥ 20%, if 0 <L * ≤ 30, in which L * is the luminosity in the color space L * a * b * (CIELAB), in which the pigment (a) is a near-infrared transparent organic pigment (NIR) and / or a reflective inorganic pigment of NIR, and coating that is an outdoor use coating selected from an industrial coating or a car coating. 2. The coating according to claim 1, wherein said coating has a TSR of

(i)

≥ 45%, if 60 <L * <100, or

(ii)

≥ 35%, if 30 <L * ≤ 60, or

(iii) ≥ 25%, if 0 <L * ≤ 30.

3.

The coating according to at least one of the preceding claims, wherein the amount of dye (b) is from 0.01 to 10.0% by weight, based on the total weight of the pigment (a).

Four.

The coating according to at least one of the preceding claims, wherein the amount of effect pigment (c) is 0.1 to 60% by weight, based on the total weight of the pigment (a).

5.

The coating according to at least one of the preceding claims, wherein the organic pigment is an NIR transparent pigment selected from the group consisting of Color Index (C.I.) Yellow Pigment 110, 139, 151; C.I. Orange Pigment 69, 73; C.I. Pigment Red 122, 179, 202, 254, 282; C.I. Brown Pigment 29; C.I. Violet Pigment 19; C.I. Blue Pigment 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 60; C.I. Green Pigment 7, 36;

C.I. Black Pigment 31, 32; a perylene pigment comprising one of the isomers of the general formula 'or Ib' or a mixture thereof, wherein R1 and R2 are the same and are naphthylene or unsubstituted phenylene; and pigment preparations of said pigments. 6. The coating according to at least one of the preceding claims, wherein the inorganic pigment is selected from the group consisting of C.I. Pigment Yellow 53, 184, C.I. Pigment Brown 24, 29, 33, 35, C.I. Pigment Blue 28, 36, C.I. Green Pigment 17, 26, 50, C.I. Pigment Black 12, 30 and pigment preparations of said pigments.

7.

The coating according to at least one of the preceding claims, wherein the pigment (a) is an organic pigment transparent to NIR, and the substrate is a metallic substrate.

8.

The coating according to at least one of the preceding claims, wherein the coating is a

5 multilayer coating, said multilayer comprises a primer, a base layer comprising one or two layers and a transparent layer as an outer layer, the organic pigment (a) is comprised in the base layer, the inorganic pigment (a) is comprised in the primer, and 10 the dye (b) is comprised in the transparent layer or in the base layer. 9. The coating according to at least one of claims 1 to 7, wherein the coating is a coating multilayer as defined in claim 8, the organic pigment (a) is comprised in the base layer, the dye (b) is comprised in the transparent layer or in the base layer, and The primer comprises a white pigment.

10.

The coating according to claim 9, wherein the base layer comprises an organic pigment (a) and an inorganic pigment (a).

eleven.

The coating according to at least one of the preceding claims, comprising

(a) a perylene pigment and / or C.I. Brown Pigment 29, 20 (b) a dye selected from the group consisting of C.I. Black solvent 27, 28 and 29, and (c) optionally, an effect pigment in which the coating has a TSR of at least 20% and L * is ≤ 30. 12. The coating according to claim 11, wherein the coating has a TSR of at least 25%, and L * is ≤ 20, preferably ≤ 15. 13. The coating according to at least one of claims 1 to 10, wherein the dye (b) is selected from the group consisting of azo dyes, azometin dyes, xanthene dyes, anthraquinone dyes, dyes of metal complex and phthalocyanine dyes. 14. The use of a dye according to claim 1 to improve the degree of blackness of a coating having a TSR of 30 (i) ≥ 40%, if 60 <L * <100, or (ii) ≥ 30%, if 30 <L * ≤ 60, or (iii) ≥ 20%, if 0 <L * ≤ 30, where L * is the luminosity in the color space L * a * b * (CIELAB), wherein the coating formed on a substrate comprises a polymeric binder, 35 (a) at least one organic pigment and / or at least one inorganic pigment;

(b)

at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y

(C)

optionally, an effect pigment,

wherein the pigment (a) is a near-infrared transparent organic pigment (NIR) and / or an inorganic pigment reflecting NIR, and 40 coating which is an exterior use coating selected from an industrial coating or a coating for automobiles. 15. A process for coating the surface of a substrate, a process that includes the consecutive stages of (i) applying a coating composition comprising a polymeric binder, and (a) at least one organic pigment and / or at least one inorganic pigment; 45 (b) at least one dye having a transmittance of at least 75% in the range of 700 to 2,500 nm; Y (c) optionally, an effect pigment; (ii) optionally, remove the solvent, and (iii) forming a coating as defined in any one of claims 1-13.